CVE-2021-28235: Go.etcd.io/etcd/v3 Etcd-io Improper Authentication Vulnerability Vulnerability

CRITICAL
Advisory Identifier: GHSA-gmph-wf7j-9gcm
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CVSS 9.8
CWE-287
Published
Advisory Summary

CVE-2021-28235 is a CRITICAL (CVSS 9.8) etcd-io improper authentication vulnerability vulnerability (CWE-287: Improper Authentication) affecting Go.etcd.io/etcd/v3 libraries in the Go ecosystem. The issue involves etcd-io improper authentication vulnerability. Remediation is available in the latest vendor maintenance releases.

CVE-2021-28235 at a Glance

CVE Identifier CVE-2021-28235
GHSA Identifier GHSA-gmph-wf7j-9gcm
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-287: Improper Authentication
Affected Product Go.etcd.io/etcd/v3
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 9.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2021-28235

To remediate this vulnerability, upgrade all affected Go.etcd.io/etcd/v3 dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

go.etcd.io/etcd/v3 fixed: Latest secure release 
Upgrade go.etcd.io/etcd/v3 to Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for go.etcd.io/etcd/v3

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-28235, inspect your project dependencies for Go.etcd.io/etcd/v3:

inspect dependencies for go.etcd.io/etcd/v3

Analyze the terminal output to locate any version of Go.etcd.io/etcd/v3 in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-287: Improper Authentication, where when an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. In Go.etcd.io/etcd/v3, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

Authentication vulnerability found in Etcd-io v.3.4.10 allows remote attackers to escalate privileges via the debug function. This has been fixed in v.[3.5.8](https://github.com/etcd-io/etcd/blob/main/CHANGELOG/CHANGELOG-3.5.md#etcd-server) and was also backported to [3.4](https://github.com/etcd-io/etcd/pull/15655) and [3.5](https://github.com/etcd-io/etcd/pull/15653).

CVE-2021-28235 Affected Go.etcd.io/etcd/v3 Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
go.etcd.io/etcd/v3
golang/go.etcd.io/etcd/v3
Go
3.4.10
All 1 versions
3.4.10
None specified

References

NVD — CVE-2021-28235 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-28235
Go.etcd.io/etcd/v3 Source Repository REPOSITORY
https://github.com/etcd-io/etcd/pull/15648
Go.etcd.io/etcd/v3 Source Repository REPOSITORY
https://github.com/etcd-io/etcd
Go.etcd.io/etcd/v3 Source Repository REPOSITORY
https://github.com/lucyxss/etcd-3.4.10-test/blob/master/temp4cj.png
Go.etcd.io/etcd/v3 Source Repository REPOSITORY
https://github.com/lucyxss/etcd-3.4.10-test/blob/master/temp4cj_2.png
etcd.com WEB
http://etcd.com

Frequently Asked Questions

What is CVE-2021-28235?
CVE-2021-28235 is a security vulnerability in Go.etcd.io/etcd/v3 involving Etcd-io Improper Authentication vulnerability under CWE-287: Improper Authentication.
Which Go.etcd.io/etcd/v3 versions are affected?
Affected versions include releases prior to current release patches across affected packages: go.etcd.io/etcd/v3.
What version fixes CVE-2021-28235?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is go.etcd.io/etcd/v3 affected?
Yes, go.etcd.io/etcd/v3 is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2021-28235?
CVE-2021-28235 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2021-28235?
CVE-2021-28235 is classified under CWE-287: Improper Authentication (When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.).
How can I check Go dependencies for CVE-2021-28235?
Run the dependency tree command: 'inspect dependencies for go.etcd.io/etcd/v3'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-gmph-wf7j-9gcm",
  "modified" : "2023-04-11T21:32:54Z",
  "published" : "2023-04-04T15:30:27Z",
  "aliases" : [ "CVE-2021-28235" ],
  "summary" : "Etcd-io Improper Authentication vulnerability",
  "details" : "Authentication vulnerability found in Etcd-io v.3.4.10 allows remote attackers to escalate privileges via the debug function.\n\nThis has been fixed in v.[3.5.8](https://github.com/etcd-io/etcd/blob/main/CHANGELOG/CHANGELOG-3.5.md#etcd-server) and was also backported to [3.4](https://github.com/etcd-io/etcd/pull/15655) and [3.5](https://github.com/etcd-io/etcd/pull/15653).",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "go.etcd.io/etcd/v3"
    },
    "versions" : [ "3.4.10" ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-28235"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/etcd-io/etcd/pull/15648"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/etcd-io/etcd"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/lucyxss/etcd-3.4.10-test/blob/master/temp4cj.png"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/lucyxss/etcd-3.4.10-test/blob/master/temp4cj_2.png"
  }, {
    "type" : "WEB",
    "url" : "http://etcd.com"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-287" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-04-11T21:32:54Z",
    "nvd_published_at" : "2023-04-04T15:15:00Z"
  }
}